1 files changed, 82 insertions, 64 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 60d6fdcc9265..5859f598c951 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -976,8 +976,6 @@ NORET_TYPE void do_exit(long code)
                 disassociate_ctty(1);
 
         module_put(task_thread_info(tsk)->exec_domain->module);
-        if (tsk->binfmt)
-                module_put(tsk->binfmt->module);
 
         proc_exit_connector(tsk);
 
@@ -1097,28 +1095,28 @@ struct wait_opts {
         int __user              *wo_stat;
         struct rusage __user    *wo_rusage;
 
+        wait_queue_t            child_wait;
         int                     notask_error;
 };
 
-static struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
+static inline
+struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
 {
-        struct pid *pid = NULL;
-        if (type == PIDTYPE_PID)
-                pid = task->pids[type].pid;
-        else if (type < PIDTYPE_MAX)
-                pid = task->group_leader->pids[type].pid;
-        return pid;
+        if (type != PIDTYPE_PID)
+                task = task->group_leader;
+        return task->pids[type].pid;
 }
 
-static int eligible_child(struct wait_opts *wo, struct task_struct *p)
+static int eligible_pid(struct wait_opts *wo, struct task_struct *p)
 {
-        int err;
-
-        if (wo->wo_type < PIDTYPE_MAX) {
-                if (task_pid_type(p, wo->wo_type) != wo->wo_pid)
-                        return 0;
-        }
+        return  wo->wo_type == PIDTYPE_MAX ||
+                task_pid_type(p, wo->wo_type) == wo->wo_pid;
+}
 
+static int eligible_child(struct wait_opts *wo, struct task_struct *p)
+{
+        if (!eligible_pid(wo, p))
+                return 0;
         /* Wait for all children (clone and not) if __WALL is set;
          * otherwise, wait for clone children *only* if __WCLONE is
          * set; otherwise, wait for non-clone children *only*.  (Note:
@@ -1128,10 +1126,6 @@ static int eligible_child(struct wait_opts *wo, struct task_struct *p)
             && !(wo->wo_flags & __WALL))
                 return 0;
 
-        err = security_task_wait(p);
-        if (err)
-                return err;
-
         return 1;
 }
 
@@ -1144,18 +1138,20 @@ static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p,
 
         put_task_struct(p);
         infop = wo->wo_info;
-        if (!retval)
-                retval = put_user(SIGCHLD, &infop->si_signo);
-        if (!retval)
-                retval = put_user(0, &infop->si_errno);
-        if (!retval)
-                retval = put_user((short)why, &infop->si_code);
-        if (!retval)
-                retval = put_user(pid, &infop->si_pid);
-        if (!retval)
-                retval = put_user(uid, &infop->si_uid);
-        if (!retval)
-                retval = put_user(status, &infop->si_status);
+        if (infop) {
+                if (!retval)
+                        retval = put_user(SIGCHLD, &infop->si_signo);
+                if (!retval)
+                        retval = put_user(0, &infop->si_errno);
+                if (!retval)
+                        retval = put_user((short)why, &infop->si_code);
+                if (!retval)
+                        retval = put_user(pid, &infop->si_pid);
+                if (!retval)
+                        retval = put_user(uid, &infop->si_uid);
+                if (!retval)
+                        retval = put_user(status, &infop->si_status);
+        }
         if (!retval)
                 retval = pid;
         return retval;
@@ -1485,13 +1481,14 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
  * then ->notask_error is 0 if @p is an eligible child,
  * or another error from security_task_wait(), or still -ECHILD.
  */
-static int wait_consider_task(struct wait_opts *wo, struct task_struct *parent,
-                                int ptrace, struct task_struct *p)
+static int wait_consider_task(struct wait_opts *wo, int ptrace,
+                                struct task_struct *p)
 {
         int ret = eligible_child(wo, p);
         if (!ret)
                 return ret;
 
+        ret = security_task_wait(p);
         if (unlikely(ret < 0)) {
                 /*
                  * If we have not yet seen any eligible child,
@@ -1553,7 +1550,7 @@ static int do_wait_thread(struct wait_opts *wo, struct task_struct *tsk)
                  * Do not consider detached threads.
                  */
                 if (!task_detached(p)) {
-                        int ret = wait_consider_task(wo, tsk, 0, p);
+                        int ret = wait_consider_task(wo, 0, p);
                         if (ret)
                                 return ret;
                 }
@@ -1567,7 +1564,7 @@ static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk)
         struct task_struct *p;
 
         list_for_each_entry(p, &tsk->ptraced, ptrace_entry) {
-                int ret = wait_consider_task(wo, tsk, 1, p);
+                int ret = wait_consider_task(wo, 1, p);
                 if (ret)
                         return ret;
         }
@@ -1575,15 +1572,38 @@ static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk)
         return 0;
 }
 
+static int child_wait_callback(wait_queue_t *wait, unsigned mode,
+                                int sync, void *key)
+{
+        struct wait_opts *wo = container_of(wait, struct wait_opts,
+                                                child_wait);
+        struct task_struct *p = key;
+
+        if (!eligible_pid(wo, p))
+                return 0;
+
+        if ((wo->wo_flags & __WNOTHREAD) && wait->private != p->parent)
+                return 0;
+
+        return default_wake_function(wait, mode, sync, key);
+}
+
+void __wake_up_parent(struct task_struct *p, struct task_struct *parent)
+{
+        __wake_up_sync_key(&parent->signal->wait_chldexit,
+                                TASK_INTERRUPTIBLE, 1, p);
+}
+
 static long do_wait(struct wait_opts *wo)
 {
-        DECLARE_WAITQUEUE(wait, current);
         struct task_struct *tsk;
         int retval;
 
         trace_sched_process_wait(wo->wo_pid);
 
-        add_wait_queue(&current->signal->wait_chldexit,&wait);
+        init_waitqueue_func_entry(&wo->child_wait, child_wait_callback);
+        wo->child_wait.private = current;
+        add_wait_queue(&current->signal->wait_chldexit, &wo->child_wait);
 repeat:
         /*
          * If there is nothing that can match our critiera just get out.
@@ -1624,32 +1644,7 @@ notask:
         }
 end:
         __set_current_state(TASK_RUNNING);
-        remove_wait_queue(&current->signal->wait_chldexit,&wait);
-        if (wo->wo_info) {
-                struct siginfo __user *infop = wo->wo_info;
-
-                if (retval > 0)
-                        retval = 0;
-                else {
-                        /*
-                         * For a WNOHANG return, clear out all the fields
-                         * we would set so the user can easily tell the
-                         * difference.
-                         */
-                        if (!retval)
-                                retval = put_user(0, &infop->si_signo);
-                        if (!retval)
-                                retval = put_user(0, &infop->si_errno);
-                        if (!retval)
-                                retval = put_user(0, &infop->si_code);
-                        if (!retval)
-                                retval = put_user(0, &infop->si_pid);
-                        if (!retval)
-                                retval = put_user(0, &infop->si_uid);
-                        if (!retval)
-                                retval = put_user(0, &infop->si_status);
-                }
-        }
+        remove_wait_queue(&current->signal->wait_chldexit, &wo->child_wait);
         return retval;
 }
 
@@ -1694,6 +1689,29 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
         wo.wo_stat      = NULL;
         wo.wo_rusage    = ru;
         ret = do_wait(&wo);
+
+        if (ret > 0) {
+                ret = 0;
+        } else if (infop) {
+                /*
+                 * For a WNOHANG return, clear out all the fields
+                 * we would set so the user can easily tell the
+                 * difference.
+                 */
+                if (!ret)
+                        ret = put_user(0, &infop->si_signo);
+                if (!ret)
+                        ret = put_user(0, &infop->si_errno);
+                if (!ret)
+                        ret = put_user(0, &infop->si_code);
+                if (!ret)
+                        ret = put_user(0, &infop->si_pid);
+                if (!ret)
+                        ret = put_user(0, &infop->si_uid);
+                if (!ret)
+                        ret = put_user(0, &infop->si_status);
+        }
+
         put_pid(pid);
 
         /* avoid REGPARM breakage on x86: */